Conventional micrometers employ a manually rotatable hollow cylinder having a shaft telescoped therein whereby rotation of the shaft in one direction or the reverse causes the shaft to be extended or retracted. Gross and fine scales on the shaft and cylinder enable the shaft position to be measured quite accurately. When different scales are required, different micrometers are used. The micrometer is normally a precision instrument using a significant number of expensive parts and assembled with care by skilled artisans.
This invention is directed toward a micrometer which can be assembled quickly and easily by unskilled labor using a few relatively inexpensive parts. A portion of the micrometer in accordance with the invention can be removed and replaced quickly and easily to change scales as required.